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<tr class="t-nv-h1"><td colspan="5"> Regular expressions</td></tr>
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<p>This header is part of the <a href="../utility/functional.html" title="cpp/utility/functional">function objects</a> library and provides the standard <a href="../utility/hash.html" title="cpp/utility/hash">hash function</a>.
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<table id="toc" class="toc"><tr><td>
<div id="toctitle"><h2>Contents</h2></div>
<ul>
<li class="toclevel-1 tocsection-1">
<a href="functional.html#Namespaces"><span class="tocnumber">1</span> <span class="toctext">Namespaces</span></a>
<ul>
<li class="toclevel-2"><a href="functional.html#Constants"><span class="tocnumber">1.1</span> <span class="toctext">Constants</span></a></li>
</ul>
</li>
<li class="toclevel-1 tocsection-2">
<a href="functional.html#Classes"><span class="tocnumber">2</span> <span class="toctext">Classes</span></a>
<ul>
<li class="toclevel-2"><a href="functional.html#Hashing"><span class="tocnumber">2.1</span> <span class="toctext">Hashing</span></a></li>
</ul>
</li>
<li class="toclevel-1 tocsection-3"><a href="functional.html#Functions"><span class="tocnumber">3</span> <span class="toctext">Functions</span></a></li>
<li class="toclevel-1 tocsection-4">
<a href="functional.html#Function_Objects"><span class="tocnumber">4</span> <span class="toctext">Function Objects</span></a>
<ul>
<li class="toclevel-2"><a href="functional.html#Arithmetic_operations"><span class="tocnumber">4.1</span> <span class="toctext">Arithmetic operations</span></a></li>
<li class="toclevel-2"><a href="functional.html#Comparisons"><span class="tocnumber">4.2</span> <span class="toctext">Comparisons</span></a></li>
<li class="toclevel-2"><a href="functional.html#Logical_operations"><span class="tocnumber">4.3</span> <span class="toctext">Logical operations</span></a></li>
<li class="toclevel-2"><a href="functional.html#Bitwise_operations"><span class="tocnumber">4.4</span> <span class="toctext">Bitwise operations</span></a></li>
<li class="toclevel-2"><a href="functional.html#Negators"><span class="tocnumber">4.5</span> <span class="toctext">Negators</span></a></li>
</ul>
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<li class="toclevel-1 tocsection-5">
<a href="functional.html#Deprecated_in_C.2B.2B11"><span class="tocnumber">5</span> <span class="toctext">Deprecated in C++11</span></a>
<ul>
<li class="toclevel-2"><a href="functional.html#Base"><span class="tocnumber">5.1</span> <span class="toctext">Base</span></a></li>
<li class="toclevel-2"><a href="functional.html#Binders"><span class="tocnumber">5.2</span> <span class="toctext">Binders</span></a></li>
<li class="toclevel-2"><a href="functional.html#Function_adaptors"><span class="tocnumber">5.3</span> <span class="toctext">Function adaptors</span></a></li>
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<li class="toclevel-1 tocsection-6">
<a href="functional.html#Synopsis"><span class="tocnumber">6</span> <span class="toctext">Synopsis</span></a>
<ul>
<li class="toclevel-2 tocsection-7"><a href="functional.html#Class_std%3A%3Areference_wrapper"><span class="tocnumber">6.1</span> <span class="toctext">Class <span>std::reference_wrapper</span></span></a></li>
<li class="toclevel-2 tocsection-8"><a href="functional.html#Class_std%3A%3Ais_bind_expression"><span class="tocnumber">6.2</span> <span class="toctext">Class <span>std::is_bind_expression</span></span></a></li>
<li class="toclevel-2 tocsection-9"><a href="functional.html#Class_std%3A%3Abad_function_call"><span class="tocnumber">6.3</span> <span class="toctext">Class <span>std::bad_function_call</span></span></a></li>
<li class="toclevel-2 tocsection-10"><a href="functional.html#Class_std%3A%3Afunction"><span class="tocnumber">6.4</span> <span class="toctext">Class <span>std::function</span></span></a></li>
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<li class="toclevel-1 tocsection-11"><a href="functional.html#See_Also"><span class="tocnumber">7</span> <span class="toctext">See Also</span></a></li>
</ul>
</td></tr></table>
<h3>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Namespaces">edit</a>]</span> <span class="mw-headline" id="Namespaces">Namespaces</span>
</h3>
<table class="t-dsc-begin">

<tr class="t-dsc">
<td> <a href="../utility/functional/placeholders.html" title="cpp/utility/functional/placeholders">placeholders</a>
</td>
<td>  Defines placeholders for the unbound arguments in a std::bind expression
</td>
</tr>


<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Constants"> Constants </span>
</h5>
</td>
</tr>

<tr class="t-dsc-header">
<td colspan="2"> <div>Defined in  namespace <code>std::placeholders</code> </div>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/placeholders.html" title="cpp/utility/functional/placeholders"> <span class="t-lines"><span>_1, _2, _3, _4, ...</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>  placeholders for the unbound arguments in a <code>std::bind</code> expression  <br> <span class="t-mark">(constant)</span> 
</td>
</tr>
</table>
<h3>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Classes">edit</a>]</span> <span class="mw-headline" id="Classes">Classes</span>
</h3>
<table class="t-dsc-begin">

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/function.html" title="cpp/utility/functional/function"> <span class="t-lines"><span>function</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>   wraps callable object of any type with specified function call signature  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/mem_fn.html" title="cpp/utility/functional/mem fn"> <span class="t-lines"><span>mem_fn</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>   creates a function object out of a pointer to a member  <br> <span class="t-mark">(function template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/bad_function_call.html" title="cpp/utility/functional/bad function call"> <span class="t-lines"><span>bad_function_call</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>   the exception thrown when invoking an empty <span class="t-lc"><a href="../utility/functional/function.html" title="cpp/utility/functional/function">std::function</a></span>  <br> <span class="t-mark">(class)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/is_bind_expression.html" title="cpp/utility/functional/is bind expression"> <span class="t-lines"><span>is_bind_expression</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>   indicates that an object is <code>std::bind</code> expression or can be used as one  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/is_placeholder.html" title="cpp/utility/functional/is placeholder"> <span class="t-lines"><span>is_placeholder</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>   indicates that an object is a standard placeholder or can be used as one  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/reference_wrapper.html" title="cpp/utility/functional/reference wrapper"> <span class="t-lines"><span>reference_wrapper</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>   <a href="../concept/CopyConstructible.html" title="cpp/concept/CopyConstructible"><code>CopyConstructible</code></a> and <a href="../concept/CopyAssignable.html" title="cpp/concept/CopyAssignable"><code>CopyAssignable</code></a> reference wrapper  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>


<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Hashing"> Hashing </span>
</h5>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/hash.html" title="cpp/utility/hash"> <span class="t-lines"><span>hash</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>   hash function object  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td> <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">bool</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<p><span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">char</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">signed</span> <span class="kw4">char</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">char</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">char16_t</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">char32_t</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">wchar_t</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">short</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">short</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">int</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">long</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">long</span> <span class="kw4">long</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">long</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">long</span> <span class="kw4">long</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">float</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">double</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">long</span> <span class="kw4">double</span><span class="sy1">&gt;</span><span class="sy4">;</span><br>
<span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> T <span class="sy1">&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span>T<span class="sy2">*</span><span class="sy1">&gt;</span><span class="sy4">;</span></p></span></span>

</td>
<td>  <span class="t-lc"><a href="../utility/hash.html" title="cpp/utility/hash">std::hash</a></span> specializations for built-in types <br> <span class="t-mark">(class template specialization)</span>
</td>
</tr>


</table>
<p><br>
</p>
<h3>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Functions">edit</a>]</span> <span class="mw-headline" id="Functions">Functions</span>
</h3>
<table class="t-dsc-begin">

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/bind.html" title="cpp/utility/functional/bind"> <span class="t-lines"><span>bind</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>   binds one or more arguments to a function object  <br> <span class="t-mark">(function template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/ref.html" title="cpp/utility/functional/ref"> <span class="t-lines"><span>ref</span><span>cref</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>   creates a <span class="t-lc"><a href="../utility/functional/reference_wrapper.html" title="cpp/utility/functional/reference wrapper">std::reference_wrapper</a></span> with a type deduced from its argument  <br> <span class="t-mark">(function template)</span> 
</td>
</tr>
</table>
<p><br>
</p>
<h3>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Function Objects">edit</a>]</span> <span class="mw-headline" id="Function_Objects">Function Objects</span>
</h3>
<table class="t-dsc-begin">

<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Arithmetic_operations">  Arithmetic operations </span>
</h5>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/plus.html" title="cpp/utility/functional/plus"> <span class="t-lines"><span>plus</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy2">+</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/minus.html" title="cpp/utility/functional/minus"> <span class="t-lines"><span>minus</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy2">-</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/multiplies.html" title="cpp/utility/functional/multiplies"> <span class="t-lines"><span>multiplies</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy2">*</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/divides.html" title="cpp/utility/functional/divides"> <span class="t-lines"><span>divides</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy2">/</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/modulus.html" title="cpp/utility/functional/modulus"> <span class="t-lines"><span>modulus</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy2">%</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/negate.html" title="cpp/utility/functional/negate"> <span class="t-lines"><span>negate</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">-</span>x</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>


<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Comparisons">  Comparisons  </span>
</h5>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/equal_to.html" title="cpp/utility/functional/equal to"> <span class="t-lines"><span>equal_to</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy1">==</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/not_equal_to.html" title="cpp/utility/functional/not equal to"> <span class="t-lines"><span>not_equal_to</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy3">!</span><span class="sy1">=</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/greater.html" title="cpp/utility/functional/greater"> <span class="t-lines"><span>greater</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy1">&gt;</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/less.html" title="cpp/utility/functional/less"> <span class="t-lines"><span>less</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy1">&lt;</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/greater_equal.html" title="cpp/utility/functional/greater equal"> <span class="t-lines"><span>greater_equal</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy1">&gt;=</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/less_equal.html" title="cpp/utility/functional/less equal"> <span class="t-lines"><span>less_equal</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy1">&lt;=</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>


<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Logical_operations">  Logical operations  </span>
</h5>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/logical_and.html" title="cpp/utility/functional/logical and"> <span class="t-lines"><span>logical_and</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy3">&amp;&amp;</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/logical_or.html" title="cpp/utility/functional/logical or"> <span class="t-lines"><span>logical_or</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy3">||</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/logical_not.html" title="cpp/utility/functional/logical not"> <span class="t-lines"><span>logical_not</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy3">!</span>x</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>


<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Bitwise_operations">  Bitwise operations  </span>
</h5>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/bit_and.html" title="cpp/utility/functional/bit and"> <span class="t-lines"><span>bit_and</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy3">&amp;</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/bit_or.html" title="cpp/utility/functional/bit or"> <span class="t-lines"><span>bit_or</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy3">|</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/bit_xor.html" title="cpp/utility/functional/bit xor"> <span class="t-lines"><span>bit_xor</span></span></a></div></div>
</td>
<td>   function object implementing <span class="t-c"><span class="mw-geshi cpp source-cpp">x <span class="sy3">^</span> y</span></span>  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>


<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Negators">  Negators  </span>
</h5>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/unary_negate.html" title="cpp/utility/functional/unary negate"> <span class="t-lines"><span>unary_negate</span></span></a></div></div>
</td>
<td>   wrapper function object returning the complement of the unary predicate it holds  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/binary_negate.html" title="cpp/utility/functional/binary negate"> <span class="t-lines"><span>binary_negate</span></span></a></div></div>
</td>
<td>   wrapper function object returning the complement of the binary predicate it holds  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/not1.html" title="cpp/utility/functional/not1"> <span class="t-lines"><span>not1</span></span></a></div></div>
</td>
<td>   constructs custom <span class="t-lc"><a href="../utility/functional/unary_negate.html" title="cpp/utility/functional/unary negate">std::unary_negate</a></span> object  <br> <span class="t-mark">(function template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div"><div><a href="../utility/functional/not2.html" title="cpp/utility/functional/not2"> <span class="t-lines"><span>not2</span></span></a></div></div>
</td>
<td>   constructs custom <span class="t-lc"><a href="../utility/functional/binary_negate.html" title="cpp/utility/functional/binary negate">std::binary_negate</a></span> object  <br> <span class="t-mark">(function template)</span> 
</td>
</tr>
</table>
<h3>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Deprecated in C++11">edit</a>]</span> <span class="mw-headline" id="Deprecated_in_C.2B.2B11">Deprecated in C++11</span>
</h3>
<table class="t-dsc-begin">

<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Base">  Base </span>
</h5>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/unary_function.html" title="cpp/utility/functional/unary function"> <span class="t-lines"><span>unary_function</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   adaptor-compatible unary function base class  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/binary_function.html" title="cpp/utility/functional/binary function"> <span class="t-lines"><span>binary_function</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   adaptor-compatible binary function base class   <br> <span class="t-mark">(class template)</span> 
</td>
</tr>


<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Binders">  Binders </span>
</h5>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/binder12.html" title="cpp/utility/functional/binder12"> <span class="t-lines"><span>binder1st</span><span>binder2nd</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   function object holding a binary function and one of its arguments  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/bind12.html" title="cpp/utility/functional/bind12"> <span class="t-lines"><span>bind1st</span><span>bind2nd</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   binds one argument to a binary function  <br> <span class="t-mark">(function template)</span> 
</td>
</tr>


<tr>
<td colspan="2"> <h5> <span class="mw-headline" id="Function_adaptors">  Function adaptors </span>
</h5>
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/pointer_to_unary_function.html" title="cpp/utility/functional/pointer to unary function"> <span class="t-lines"><span>pointer_to_unary_function</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   adaptor-compatible wrapper for a pointer to unary function  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/pointer_to_binary_function.html" title="cpp/utility/functional/pointer to binary function"> <span class="t-lines"><span>pointer_to_binary_function</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   adaptor-compatible wrapper for a pointer to binary function  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/ptr_fun.html" title="cpp/utility/functional/ptr fun"> <span class="t-lines"><span>ptr_fun</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   creates an adaptor-compatible function object wrapper from a pointer to function  <br> <span class="t-mark">(function template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/mem_fun_t.html" title="cpp/utility/functional/mem fun t"> <span class="t-lines"><span>mem_fun_t</span><span>mem_fun1_t</span><span>const_mem_fun_t</span><span>const_mem_fun1_t</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   wrapper for a pointer to nullary or unary member function, callable with a pointer to object  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/mem_fun.html" title="cpp/utility/functional/mem fun"> <span class="t-lines"><span>mem_fun</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   creates a wrapper from a pointer to member function, callable with a pointer to object <br> <span class="t-mark">(function template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/mem_fun_ref_t.html" title="cpp/utility/functional/mem fun ref t"> <span class="t-lines"><span>mem_fun_ref_t</span><span>mem_fun1_ref_t</span><span>const_mem_fun_ref_t</span><span>const_mem_fun1_ref_t</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   wapper for a pointer to nullary or unary member function, callable with a reference to object  <br> <span class="t-mark">(class template)</span> 
</td>
</tr>

<tr class="t-dsc">
<td>  <div class="t-dsc-member-div">
<div><a href="../utility/functional/mem_fun_ref.html" title="cpp/utility/functional/mem fun ref"> <span class="t-lines"><span>mem_fun_ref</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-until-cxx17">(until C++17)</span></span></span></div>
</div>
</td>
<td>   creates a wrapper from a pointer to member function, callable with a reference to object <br> <span class="t-mark">(function template)</span> 
</td>
</tr>
</table>
<h3>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Synopsis">edit</a>]</span> <span class="mw-headline" id="Synopsis">Synopsis</span>
</h3>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">namespace</span> std <span class="br0">{</span>
 
    <span class="co1">// base (deprecated):</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Arg, <span class="kw1">class</span> Result<span class="sy1">&gt;</span> <span class="kw1">struct</span> unary_function<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Arg1, <span class="kw1">class</span> Arg2, <span class="kw1">class</span> Result<span class="sy1">&gt;</span> <span class="kw1">struct</span> binary_function<span class="sy4">;</span>
 
    <span class="co1">// reference_wrapper:</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">class</span> reference_wrapper<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> reference_wrapper<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span> ref<span class="br0">(</span>T<span class="sy3">&amp;</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> reference_wrapper<span class="sy1">&lt;</span><span class="kw4">const</span> T<span class="sy1">&gt;</span> cref<span class="br0">(</span><span class="kw4">const</span> T<span class="sy3">&amp;</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw4">void</span> ref<span class="br0">(</span><span class="kw4">const</span> T<span class="sy3">&amp;&amp;</span><span class="br0">)</span> <span class="sy1">=</span> delete<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw4">void</span> cref<span class="br0">(</span><span class="kw4">const</span> T<span class="sy3">&amp;&amp;</span><span class="br0">)</span> <span class="sy1">=</span> delete<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> reference_wrapper<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span> ref<span class="br0">(</span>reference_wrapper<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> reference_wrapper<span class="sy1">&lt;</span><span class="kw4">const</span> T<span class="sy1">&gt;</span> cref<span class="br0">(</span>reference_wrapper<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
 
    <span class="co1">// arithmetic operations:</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> plus<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> minus<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> multiplies<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> divides<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> modulus<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> negate<span class="sy4">;</span>
 
    <span class="co1">// comparisons:</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> equal_to<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> not_equal_to<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> greater<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> less<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> greater_equal<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> less_equal<span class="sy4">;</span>
 
    <span class="co1">// logical operations:</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> logical_and<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> logical_or<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> logical_not<span class="sy4">;</span>
 
    <span class="co1">// bitwise operations:</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> bit_and<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> bit_or<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> bit_xor<span class="sy4">;</span>
 
    <span class="co1">// negators:</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Predicate<span class="sy1">&gt;</span> <span class="kw1">class</span> unary_negate<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Predicate<span class="sy1">&gt;</span>
        unary_negate<span class="sy1">&lt;</span>Predicate<span class="sy1">&gt;</span> 
        not1<span class="br0">(</span><span class="kw4">const</span> Predicate<span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Predicate<span class="sy1">&gt;</span>  <span class="kw1">class</span> binary_negate<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Predicate<span class="sy1">&gt;</span>
        binary_negate<span class="sy1">&lt;</span>Predicate<span class="sy1">&gt;</span>
        not2<span class="br0">(</span><span class="kw4">const</span> Predicate<span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
 
    <span class="co1">// bind:</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> is_bind_expression<span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> is_placeholder<span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span>  F, <span class="kw1">class</span>... <span class="me1">BoundArgs</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> bind<span class="br0">(</span>F<span class="sy3">&amp;&amp;</span>, BoundArgs<span class="sy3">&amp;&amp;</span>...<span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span>  R, <span class="kw1">class</span> F, <span class="kw1">class</span>... <span class="me1">BoundArgs</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> bind<span class="br0">(</span>F<span class="sy3">&amp;&amp;</span>, BoundArgs<span class="sy3">&amp;&amp;</span>...<span class="br0">)</span><span class="sy4">;</span>
 
    <span class="kw1">namespace</span> placeholders <span class="br0">{</span>
        <span class="co1">// M is the implementation-defined number of placeholders</span>
        <span class="kw4">extern</span> <span class="coMULTI">/*unspecified*/</span> _1<span class="sy4">;</span>
        <span class="kw4">extern</span> <span class="coMULTI">/*unspecified*/</span> _2<span class="sy4">;</span>
        .
        .
        .
        <span class="kw4">extern</span> <span class="coMULTI">/*unspecified*/</span> _M<span class="sy4">;</span>
    <span class="br0">}</span>
 
    <span class="co1">// binders (deprecated):</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Fn<span class="sy1">&gt;</span> <span class="kw1">class</span> binder1st<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Fn, <span class="kw1">class</span> T<span class="sy1">&gt;</span>
        binder1st<span class="sy1">&lt;</span>Fn<span class="sy1">&gt;</span> bind1st<span class="br0">(</span><span class="kw4">const</span> Fn<span class="sy3">&amp;</span>, <span class="kw4">const</span> T<span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Fn<span class="sy1">&gt;</span> <span class="kw1">class</span> binder2nd<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Fn, <span class="kw1">class</span> T<span class="sy1">&gt;</span>
        binder2nd<span class="sy1">&lt;</span>Fn<span class="sy1">&gt;</span> bind2nd<span class="br0">(</span><span class="kw4">const</span> Fn<span class="sy3">&amp;</span>, <span class="kw4">const</span> T<span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
 
    <span class="co1">// adaptors (deprecated):</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Arg, <span class="kw1">class</span> Result<span class="sy1">&gt;</span> <span class="kw1">class</span> pointer_to_unary_function<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Arg, <span class="kw1">class</span> Result<span class="sy1">&gt;</span>
        pointer_to_unary_function<span class="sy1">&lt;</span>Arg,Result<span class="sy1">&gt;</span> ptr_fun<span class="br0">(</span>Result <span class="br0">(</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Arg<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Arg1, <span class="kw1">class</span> Arg2, <span class="kw1">class</span> Result<span class="sy1">&gt;</span>
        <span class="kw1">class</span> pointer_to_binary_function<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Arg1, <span class="kw1">class</span> Arg2, <span class="kw1">class</span> Result<span class="sy1">&gt;</span>
        pointer_to_binary_function<span class="sy1">&lt;</span>Arg1,Arg2,Result<span class="sy1">&gt;</span>
        ptr_fun<span class="br0">(</span>Result <span class="br0">(</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Arg1,Arg2<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
 
    <span class="co1">// adaptors (deprecated):</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">class</span> mem_fun_t<span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T, <span class="kw1">class</span> A<span class="sy1">&gt;</span> <span class="kw1">class</span> mem_fun1_t<span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T<span class="sy1">&gt;</span>
        mem_fun_t<span class="sy1">&lt;</span>S,T<span class="sy1">&gt;</span> mem_fun<span class="br0">(</span>S <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span>f<span class="br0">)</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T, <span class="kw1">class</span> A<span class="sy1">&gt;</span>
        mem_fun1_t<span class="sy1">&lt;</span>S,T,A<span class="sy1">&gt;</span> mem_fun<span class="br0">(</span>S <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span>f<span class="br0">)</span><span class="br0">(</span>A<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">class</span> mem_fun_ref_t<span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T, <span class="kw1">class</span> A<span class="sy1">&gt;</span> <span class="kw1">class</span> mem_fun1_ref_t<span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T<span class="sy1">&gt;</span>
        mem_fun_ref_t<span class="sy1">&lt;</span>S,T<span class="sy1">&gt;</span> mem_fun_ref<span class="br0">(</span>S <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span>f<span class="br0">)</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T, <span class="kw1">class</span> A<span class="sy1">&gt;</span>
        mem_fun1_ref_t<span class="sy1">&lt;</span>S,T,A<span class="sy1">&gt;</span> mem_fun_ref<span class="br0">(</span>S <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span>f<span class="br0">)</span><span class="br0">(</span>A<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">class</span> const_mem_fun_t<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T, <span class="kw1">class</span> A<span class="sy1">&gt;</span> <span class="kw1">class</span> const_mem_fun1_t<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T<span class="sy1">&gt;</span>
        const_mem_fun_t<span class="sy1">&lt;</span>S,T<span class="sy1">&gt;</span> mem_fun<span class="br0">(</span>S <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span>f<span class="br0">)</span><span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T, <span class="kw1">class</span> A<span class="sy1">&gt;</span>
        const_mem_fun1_t<span class="sy1">&lt;</span>S,T,A<span class="sy1">&gt;</span> mem_fun<span class="br0">(</span>S <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span>f<span class="br0">)</span><span class="br0">(</span>A<span class="br0">)</span> <span class="kw4">const</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">class</span> const_mem_fun_ref_t<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T, <span class="kw1">class</span> A<span class="sy1">&gt;</span> <span class="kw1">class</span> const_mem_fun1_ref_t<span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T<span class="sy1">&gt;</span>
        const_mem_fun_ref_t<span class="sy1">&lt;</span>S,T<span class="sy1">&gt;</span> mem_fun_ref<span class="br0">(</span>S <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span>f<span class="br0">)</span><span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> S, <span class="kw1">class</span> T, <span class="kw1">class</span> A<span class="sy1">&gt;</span>
        const_mem_fun1_ref_t<span class="sy1">&lt;</span>S,T,A<span class="sy1">&gt;</span> mem_fun_ref<span class="br0">(</span>S <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span>f<span class="br0">)</span><span class="br0">(</span>A<span class="br0">)</span> <span class="kw4">const</span><span class="br0">)</span><span class="sy4">;</span>
 
    <span class="co1">// member function adaptors:</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="kw4">const</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="kw4">volatile</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="kw4">const</span> <span class="kw4">volatile</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="kw4">const</span> <span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="kw4">volatile</span> <span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="kw4">const</span> <span class="kw4">volatile</span> <span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="sy3">&amp;&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="kw4">const</span> <span class="sy3">&amp;&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="kw4">volatile</span> <span class="sy3">&amp;&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span> T, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span>
        <span class="coMULTI">/*unspecified*/</span> mem_fn<span class="br0">(</span>R <span class="br0">(</span>T<span class="sy4">::</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">(</span>Args...<span class="br0">)</span> <span class="kw4">const</span> <span class="kw4">volatile</span> <span class="sy3">&amp;&amp;</span><span class="br0">)</span><span class="sy4">;</span>
 
    <span class="co1">// polymorphic function wrappers:</span>
    <span class="kw1">class</span> bad_function_call<span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span><span class="sy1">&gt;</span> <span class="kw1">class</span> function<span class="sy4">;</span> <span class="co1">// undefined</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span>... <span class="me1">ArgTypes</span><span class="sy1">&gt;</span> <span class="kw1">class</span> function<span class="sy1">&lt;</span>R<span class="br0">(</span>ArgTypes...<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span>... <span class="me1">ArgTypes</span><span class="sy1">&gt;</span>
        <span class="kw4">void</span> swap<span class="br0">(</span>function<span class="sy1">&lt;</span>R<span class="br0">(</span>ArgTypes...<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy3">&amp;</span>, function<span class="sy1">&lt;</span>R<span class="br0">(</span>ArgTypes...<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span>... <span class="me1">ArgTypes</span><span class="sy1">&gt;</span>
        <span class="kw4">bool</span> operator<span class="sy1">==</span><span class="br0">(</span><span class="kw4">const</span> function<span class="sy1">&lt;</span>R<span class="br0">(</span>ArgTypes...<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy3">&amp;</span>, nullptr_t<span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span>... <span class="me1">ArgTypes</span><span class="sy1">&gt;</span>
        <span class="kw4">bool</span> operator<span class="sy1">==</span><span class="br0">(</span>nullptr_t, <span class="kw4">const</span> function<span class="sy1">&lt;</span>R<span class="br0">(</span>ArgTypes...<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span>... <span class="me1">ArgTypes</span><span class="sy1">&gt;</span>
        <span class="kw4">bool</span> operator<span class="sy3">!</span><span class="sy1">=</span><span class="br0">(</span><span class="kw4">const</span> function<span class="sy1">&lt;</span>R<span class="br0">(</span>ArgTypes...<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy3">&amp;</span>, nullptr_t<span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span>... <span class="me1">ArgTypes</span><span class="sy1">&gt;</span>
        <span class="kw4">bool</span> operator<span class="sy3">!</span><span class="sy1">=</span><span class="br0">(</span>nullptr_t, <span class="kw4">const</span> function<span class="sy1">&lt;</span>R<span class="br0">(</span>ArgTypes...<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
 
    <span class="co1">// hash function base template:</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> hash<span class="sy4">;</span>
 
    <span class="co1">// Hash function specializations</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">bool</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">char</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">signed</span> <span class="kw4">char</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">char</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">char16_t</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">char32_t</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">wchar_t</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">short</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">short</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">int</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">long</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">long</span> <span class="kw4">long</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">long</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">unsigned</span> <span class="kw4">long</span> <span class="kw4">long</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">float</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">double</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span><span class="kw4">long</span> <span class="kw4">double</span><span class="sy1">&gt;</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> hash<span class="sy1">&lt;</span>T<span class="sy2">*</span><span class="sy1">&gt;</span><span class="sy4">;</span>
 
<span class="br0">}</span></pre></div></div>
<p><br>
</p>
<h4>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Class std::reference wrapper">edit</a>]</span> <span class="mw-headline" id="Class_std::reference_wrapper">Class <span class="t-lc"><a href="../utility/functional/reference_wrapper.html" title="cpp/utility/functional/reference wrapper">std::reference_wrapper</a></span></span>
</h4>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">class</span> reference_wrapper <span class="br0">{</span>
<span class="kw1">public</span> <span class="sy4">:</span>
    <span class="co1">// types</span>
    <span class="kw1">typedef</span> T type<span class="sy4">;</span>
    <span class="kw1">typedef</span> <span class="coMULTI">/*Return type of T*/</span>     result_type<span class="sy4">;</span>          <span class="co1">// not always defined</span>
    <span class="kw1">typedef</span> <span class="coMULTI">/*Single argument of T*/</span> argument_type<span class="sy4">;</span>        <span class="co1">// not always defined</span>
    <span class="kw1">typedef</span> <span class="coMULTI">/*1st argument of T*/</span>    first_argument_type<span class="sy4">;</span>  <span class="co1">// not always defined</span>
    <span class="kw1">typedef</span> <span class="coMULTI">/*2nd argument of T*/</span>    second_argument_type<span class="sy4">;</span> <span class="co1">// not always defined</span>
 
    <span class="co1">// construct/copy/destroy</span>
    reference_wrapper<span class="br0">(</span>T<span class="sy3">&amp;</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    reference_wrapper<span class="br0">(</span>T<span class="sy3">&amp;&amp;</span><span class="br0">)</span> <span class="sy1">=</span> delete<span class="sy4">;</span>
 
    <span class="co1">// do not bind to temporary objects</span>
    reference_wrapper<span class="br0">(</span><span class="kw4">const</span> reference_wrapper<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> x<span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
 
    <span class="co1">// assignment</span>
    reference_wrapper<span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span><span class="kw4">const</span> reference_wrapper<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> x<span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
 
    <span class="co1">// access</span>
    operator T<span class="sy3">&amp;</span> <span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    T<span class="sy3">&amp;</span> get<span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
 
    <span class="co1">// invocation</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span>... <span class="me1">ArgTypes</span><span class="sy1">&gt;</span>
        <span class="kw1">typename</span> result_of<span class="sy1">&lt;</span>T<span class="sy3">&amp;</span><span class="br0">(</span>ArgTypes<span class="sy3">&amp;&amp;</span>...<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy4">::</span><span class="me2">type</span>
        operator<span class="br0">(</span><span class="br0">)</span> <span class="br0">(</span>ArgTypes<span class="sy3">&amp;&amp;</span>...<span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span>
 
<span class="br0">}</span><span class="sy4">;</span></pre></div></div>
<h4>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Class std::is bind expression">edit</a>]</span> <span class="mw-headline" id="Class_std::is_bind_expression">Class <span class="t-lc"><a href="../utility/functional/is_bind_expression.html" title="cpp/utility/functional/is bind expression">std::is_bind_expression</a></span></span>
</h4>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> T<span class="sy1">&gt;</span> <span class="kw1">struct</span> is_bind_expression
    <span class="sy4">:</span> integral_constant<span class="sy1">&lt;</span><span class="kw4">bool</span>, <span class="coMULTI">/*true</span></pre></div></div>
<p><br>
</p>
<h4>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Class std::bad function call">edit</a>]</span> <span class="mw-headline" id="Class_std::bad_function_call">Class <span class="t-lc"><a href="../utility/functional/bad_function_call.html" title="cpp/utility/functional/bad function call">std::bad_function_call</a></span></span>
</h4>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">class</span> bad_function_call <span class="sy4">:</span> <span class="kw1">public</span> <a href="../error/exception.html"><span class="kw611">std::<span class="me2">exception</span></span></a> <span class="br0">{</span>
<span class="kw1">public</span><span class="sy4">:</span>
    <span class="co1">// constructor:</span>
    bad_function_call<span class="br0">(</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
<span class="br0">}</span><span class="sy4">;</span></pre></div></div>
<h4>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: Class std::function">edit</a>]</span> <span class="mw-headline" id="Class_std::function">Class <span class="t-lc"><a href="../utility/functional/function.html" title="cpp/utility/functional/function">std::function</a></span></span>
</h4>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span><span class="sy1">&gt;</span> <span class="kw1">class</span> function<span class="sy4">;</span> <span class="co1">// undefined</span>
 
<span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> R, <span class="kw1">class</span>... <span class="me1">ArgTypes</span><span class="sy1">&gt;</span>
<span class="kw1">class</span> function<span class="sy1">&lt;</span>R<span class="br0">(</span>ArgTypes...<span class="br0">)</span><span class="sy1">&gt;</span> <span class="br0">{</span>
<span class="kw1">public</span><span class="sy4">:</span>
    <span class="kw1">typedef</span> R result_type<span class="sy4">;</span>      
    <span class="kw1">typedef</span> T1 argument_type<span class="sy4">;</span>       <span class="co1">//  iff sizeof...(ArgTypes) == 1 and</span>
                                    <span class="co1">//  the type in ArgTypes is T1</span>
    <span class="kw1">typedef</span> T1 first_argument_type<span class="sy4">;</span> <span class="co1">//  iff sizeof...(ArgTypes) == 2 and</span>
                                    <span class="co1">//  ArgTypes contains T1 and T2</span>
    <span class="kw1">typedef</span> T2 second_argument_type<span class="sy4">;</span><span class="co1">//  iff sizeof...(ArgTypes) == 2 and</span>
                                    <span class="co1">//  ArgTypes contains T1 and T2</span>
 
    <span class="co1">// construct/copy/destroy:</span>
    function<span class="br0">(</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    function<span class="br0">(</span>nullptr_t<span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    function<span class="br0">(</span><span class="kw4">const</span> function<span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    function<span class="br0">(</span>function<span class="sy3">&amp;&amp;</span><span class="br0">)</span><span class="sy4">;</span>
 
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> F<span class="sy1">&gt;</span> function<span class="br0">(</span>F<span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> A<span class="sy1">&gt;</span> function<span class="br0">(</span>allocator_arg_t, <span class="kw4">const</span> A<span class="sy3">&amp;</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> A<span class="sy1">&gt;</span> function<span class="br0">(</span>allocator_arg_t, <span class="kw4">const</span> A<span class="sy3">&amp;</span>, nullptr_t<span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> A<span class="sy1">&gt;</span> function<span class="br0">(</span>allocator_arg_t, <span class="kw4">const</span> A<span class="sy3">&amp;</span>, <span class="kw4">const</span> function<span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> A<span class="sy1">&gt;</span> function<span class="br0">(</span>allocator_arg_t, <span class="kw4">const</span> A<span class="sy3">&amp;</span>, function<span class="sy3">&amp;&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> F, <span class="kw1">class</span> A<span class="sy1">&gt;</span> function<span class="br0">(</span>allocator_arg_t, <span class="kw4">const</span> A<span class="sy3">&amp;</span>, F<span class="br0">)</span><span class="sy4">;</span>
 
    function<span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span><span class="kw4">const</span> function<span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    function<span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span>function<span class="sy3">&amp;&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    function<span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span>nullptr_t<span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> F<span class="sy1">&gt;</span> function<span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span>F<span class="sy3">&amp;&amp;</span><span class="br0">)</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> F<span class="sy1">&gt;</span> function<span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span>reference_wrapper<span class="sy1">&lt;</span>F<span class="sy1">&gt;</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
 
    ~function<span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span>
 
    <span class="co1">// function modifiers:</span>
    <span class="kw4">void</span> swap<span class="br0">(</span>function<span class="sy3">&amp;</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    <span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> F, <span class="kw1">class</span> A<span class="sy1">&gt;</span> <span class="kw4">void</span> assign<span class="br0">(</span>F<span class="sy3">&amp;&amp;</span>, <span class="kw4">const</span> A<span class="sy3">&amp;</span><span class="br0">)</span><span class="sy4">;</span>
 
    <span class="co1">// function capacity:</span>
    <span class="kw1">explicit</span> operator <span class="kw4">bool</span><span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
 
    <span class="co1">// function invocation:</span>
    R operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span>ArgTypes...<span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span>
 
    <span class="co1">// function target access:</span>
    <span class="kw4">const</span> <a href="../types/type_info.html"><span class="kw437">std::<span class="me2">type_info</span></span></a><span class="sy3">&amp;</span> target_type<span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">typename</span> T<span class="sy1">&gt;</span>       T<span class="sy2">*</span> target<span class="br0">(</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
    <span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">typename</span> T<span class="sy1">&gt;</span> <span class="kw4">const</span> T<span class="sy2">*</span> target<span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span>
 
<span class="br0">}</span><span class="sy4">;</span></pre></div></div>
<p><br>
</p>
<h3>
<span class="editsection">[<a href="http%3A//en.cppreference.com/mwiki/index.php" title="Edit section: See Also">edit</a>]</span> <span class="mw-headline" id="See_Also">See Also</span>
</h3>
<table class="t-dsc-begin">

<tr class="t-dsc">
<td> <a href="string.html" title="cpp/header/string"><tt>&lt;string&gt;</tt></a>
</td>
<td> Specializes <span class="t-lc"><a href="../utility/hash.html" title="cpp/utility/hash">std::hash</a></span> for <span class="t-lc"><a href="../string/basic_string.html" title="cpp/string/basic string">std::string</a></span>, <span class="t-lc"><a href="../string/basic_string.html" title="cpp/string/basic string">std::u16string</a></span>,  <span class="t-lc"><a href="../string/basic_string.html" title="cpp/string/basic string">std::u32string</a></span>,  <span class="t-lc"><a href="../string/basic_string.html" title="cpp/string/basic string">std::wstring</a></span>
</td>
</tr>


<tr class="t-dsc">
<td> <a href="system_error.html" title="cpp/header/system error"><tt>&lt;system_error&gt;</tt></a>
</td>
<td> Specializes <span class="t-lc"><a href="../utility/hash.html" title="cpp/utility/hash">std::hash</a></span> for <span class="t-lc"><a href="../error/error_code.html" title="cpp/error/error code">std::error_code</a></span>
</td>
</tr>


<tr class="t-dsc">
<td> <a href="bitset.html" title="cpp/header/bitset"><tt>&lt;bitset&gt;</tt></a>
</td>
<td> Specializes <span class="t-lc"><a href="../utility/hash.html" title="cpp/utility/hash">std::hash</a></span> for <span class="t-lc"><a href="../utility/bitset.html" title="cpp/utility/bitset">std::bitset</a></span>
</td>
</tr>


<tr class="t-dsc">
<td> <a href="memory.html" title="cpp/header/memory"><tt>&lt;memory&gt;</tt></a>
</td>
<td> Specializes <span class="t-lc"><a href="../utility/hash.html" title="cpp/utility/hash">std::hash</a></span> for <span class="t-lc"><a href="../memory/unique_ptr.html" title="cpp/memory/unique ptr">std::unique_ptr</a></span>, <span class="t-lc"><a href="../memory/shared_ptr.html" title="cpp/memory/shared ptr">std::shared_ptr</a></span>
</td>
</tr>


<tr class="t-dsc">
<td> <a href="typeindex.html" title="cpp/header/typeindex"><tt>&lt;typeindex&gt;</tt></a>
</td>
<td> Specializes <span class="t-lc"><a href="../utility/hash.html" title="cpp/utility/hash">std::hash</a></span> for <span class="t-lc"><a href="../types/type_index.html" title="cpp/types/type index">std::type_index</a></span>
</td>
</tr>


<tr class="t-dsc">
<td> <a href="vector.html" title="cpp/header/vector"><tt>&lt;vector&gt;</tt></a>
</td>
<td> Specializes <span class="t-lc"><a href="../utility/hash.html" title="cpp/utility/hash">std::hash</a></span> for <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="../container/vector.html"><span class="kw1064">std::<span class="me2">vector</span></span></a><span class="sy1">&lt;</span><span class="kw4">bool</span><span class="sy1">&gt;</span></span></span>
</td>
</tr>


<tr class="t-dsc">
<td> <a href="thread.html" title="cpp/header/thread"><tt>&lt;thread&gt;</tt></a>
</td>
<td> Specializes <span class="t-lc"><a href="../utility/hash.html" title="cpp/utility/hash">std::hash</a></span> for <span class="t-lc"><a href="../thread/thread/id.1.html" title="cpp/thread/thread/id">std::thread::id</a></span>
</td>
</tr>

</table>

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